Commonly assigned, copending application Ser. No. 831,709, filed Sept. 9, 1977, discloses a system for protecting a power distribution circuit against ground faults wherein a conventional, residential ground fault circuit interrupter (GFCI) acts in response to a fault signal developed by a ground fault sensor associated with the power circuit to effect closure of a normally open, accessory mechanical switch wired into an energization circuit for a shunt trip solenoid of a power circuit breaker protecting the power circuit. The resulting energization of this solenoid trips the power circuit breaker contacts open to interrupt the power distribution circuit, clearing the ground fault condition thereon. For certain GFCI device constructions, the physical adaption thereto of a normally open, accessory mechanical switch is not structurally convenient. This is particularly so in the case of GFCI devices in receptacle configurations.
It is accordingly an object of the present invention to provide a ground fault protection system of the type discloses in the above-noted copending application, wherein the GFCI device is adapted to effect closure of a normally open solid state, i.e., non-mechanical, accessory switch pursuant to shunt tripping a power circuit breaker.
An additional object is to provide a ground fault protection system of the above character, wherein the solid state accessory switch is effectively electrically isolated from the GFCI device for electrical noise immunity.
A further object is to provide a ground fault protection system of the above character, wherein the accessory switch is a light activated, solid state switch optically coupled with the GFCI device.
Other objects of the invention will in part be obvious and in part appear hereinafter.